Microsurgical Resection of Tuberculum Sellae Meningioma through Pterional Approach with Extradural Optic Canal Unroofing

Tuberculum sellae meningiomas pose significant challenges because they are surrounded by crucial neurovascular structures, such as the optic and oculomotor nerves, pituitary stalk, internal carotid artery and its branches, and the anterior cerebral arteries. Even if small, such meningiomas frequently extend to the optic canal that is considered a poor prognostic factor for vision. In this video clip, we illustrate the case of a 60-year-old female who had an approximately 3-cm tuberculum sellae meningioma with optic canal involvement. She underwent surgical resection of the tumor through a pterional approach. After extradural optic canal unroofing, detaching, devascularizing, and debulking the tumor, careful dissection of the meningioma from the surrounding tissues was performed. Next, the tumor extensions into both of the optic canals were removed. Finally, coagulation and resection of the tumor origin on the dura of the tuberculum sellae following Simpson's grade-I resection were performed. Histopathology revealed that the tumor was a World Health Organization (WHO) grade-I meningioma. The patient had an uneventful postoperative course and her visual acuity was preserved, with no visual field defect on postoperative visual examination. In this video, the basic surgical techniques in performing extradural optic canal unroofing, preserving the arachnoid plane, and stay in collect layer, which is the essential technique for dissecting meningiomas and for preserving neurovascular structures, are demonstrated.The link to the video can be found at: https://youtu.be/vD54Iji0C4Q.

Strategies for Optic Pathways Decompression for Extra-Axial Tumors or Intracranial Aneurysms: A Technical Note

Background Different types of skull base tumors and intracranial aneurysms may lead to compression of the optic pathways. Since most of them are biologically benign conditions, the first aim of surgery is preservation of optic nerves rather than the oncologic radicality. Materials and methods Based on the progressive technical refinements coming from our institutional experience of optic nerve compression from aneurysms and extra-axial tumors, we analyzed the surgical steps to release nerves and chiasm during tumor debulking and aneurysm clipping. Results We distinguished vascular and tumor lesions according to the main direction of optic nerve compression: lateral to medial, medial to lateral, inferior to superior, and anterior to posterior. We also identified four fundamental sequential maneuvers to release the optic nerve, which are (1) falciform ligament (FL) section, (2) optic canal unroofing, (3) anterior clinoid process drilling, and (4) optic strut removal. The FL section is always recommended when a gentle manipulation of the optic nerve is required. Optic canal unroofing is suggested in case of lateral-to-medial compression (i.e., clinoid meningiomas), medial-to-lateral compression (i.e., tuberculum sellae meningiomas), and inferior-to-superior compression (i.e., suprasellar lesions). Anterior clinoidectomy and optic strut removal may be necessary in case of lateral-to-medial compression from paraclinoid aneurysms or meningiomas. Conclusions Preservation of the visual function is the main goal of surgery for tumors and aneurysms causing optic nerve compression. This mandatory principle guides the approach, the timing, and the technical strategy to release the optic nerve, and is principally based on the direction of the compression vector.

Tailored Optic Unroofing for Type III Clinoidal Meningioma: Description of a Surgical Technique

Background: Anterior clinoidal meningiomas are heterogeneous types of lesions that comprise the parasellar lesions group. Due to their close relationship with the optic nerve and internal carotid artery, they become challenging pathologies for neurosurgeons. Case Description: Female 47, presented with superior temporal quadrantanopsia on the right side. Magnetic resonance image revealed type III clinoidal meningioma on the right side. She has undergone a pterional craniotomy for an optic canal unroofing and tumor extraction. Two years of postoperative follow-up the patient underwent a campimetry, which revealed an almost complete visual improvement. Conclusion: To date, the best surgical technique has not yet been defined, so the choice of treatment and surgical technique is based on each case and on the surgeons’ experience.

Direct Surgery of Previously Coiled Large Internal Carotid Ophthalmic Aneurysm for the Purpose of Optic Nerve Decompression

Background Progressive visual loss after coil embolization of a large internal carotid ophthalmic aneurysm has been widely reported. It is generally accepted that the primary strategy for this complication should be conservative, including steroid therapy; however, it is not well known as to what approach to take when the conservative therapy is not effective. Case Presentation We report a case of a 55-year-old female presenting with progressive visual loss after the coiling of a ruptured large internal carotid ophthalmic aneurysm. As the conservative therapy had not been effective, we performed neck clipping of the aneurysm with optic canal unroofing, anterior clinoidectomy, and partial removal of the embolized coils for the purpose of optic nerve decompression. After the surgery, the visual symptom was improved markedly. Conclusions It is suggested that direct surgery for the purpose of optic nerve decompression may be one of the options when conservative therapy is not effective for progressive visual disturbance after coil embolization.

EFFECT OF EARLY OPTIC CANAL UNROOFING ON THE OUTCOME OF VISUAL FUNCTIONS IN SURGERY FOR MENINGIOMAS OF THE TUBERCULUM SELLAE AND PLANUM SPHENOIDALE

OBJECTIVE The aim of this study was to evaluate the effect of early optic canal unroofing on visual function in patients with meningiomas of the tuberculum sellae and planum sphenoidale. METHODS We retrospectively reviewed the clinical records of 20 consecutive patients with tuberculum sellae meningiomas and two patients with planum sphenoidale meningiomas who were admitted to our institution from 1999 to 2007. Factors that may influence postoperative visual functions were analyzed, including patient's age and sex, duration of preoperative visual symptoms, preoperative visual acuity, tumor size, tumor consistency, tumor extension into the optic canal, tumor adhesion to the optic nerve, timing of optic canal unroofing, and tumor resection rate. RESULTS The mean patient age was 52.9 ± 13.7 years (range, 27–73 yr); 18 patients were women and four were men. The mean maximum tumor size was 2.3 ± 0.7 cm (range, 1.5–3.5 cm). Visual symptoms were present preoperatively in 19 patients, and three patients were asymptomatic. The mean duration of visual symptoms was 12.0 ± 16.4 months (range, 0–72 mo). Tumor resection was evaluated according to Simpson's grade, and Grade II was achieved in 14, Grade III in two, and Grade IV in six (two patients were recurrent cases). Tumors were extended into the optic canal in 15 patients, and severe adhesion to the optic nerve was observed in nine patients. Tumor consistency was soft in eight patients, intermediate in eight patients, and hard in six patients. The optic canal was unroofed early before dissection or manipulation of tumor in nine patients (early group) and after dissection of tumor in seven patients (late group), and optic canal unroofing was not performed in six patients (none group; no canal extension in two and intentional incomplete resection in four patients). Visual symptoms were improved in 10 patients, unchanged in seven patients, and worsened in five patients (transient in two and permanent in three). Logistic regression analysis revealed that early optic canal unroofing was an independent factor for postoperative improvement of visual symptoms. CONCLUSION Early optic canal unroofing may increase the possibility of improved preoperative visual symptoms in surgical resection of tuberculum sellae meningiomas and planum sphenoidale meningiomas.